POC: [NX-496] Component metadata api

https://issues.sonatype.org/browse/NX-496
I would expect to see a method that returns all metadata of specified types - is that going to be part of the API?

Like:

Map<String, Object> retrieveMetadata(String componentIdentity, String... metadataTypes)

Wondering how it fits in because MetadataStore is only parameterized to one Type.